The present invention relates to a method and an apparatus for separately displaying in braille the information appearing on a cathode-ray-tube (CRT) screen, using a shape memory resin as a display medium.
For the purposes of the invention the term "braille" is intended not merely to mean the braille in a limited sense but to encompass all other representations of characters, symbols, and patterns in tangible forms for reading by touch. By a "braille web" is meant any web or web-like layer for recording the braille. The expression "recovery of the braille web" is used to mean correcting or erasing part or whole of the braille and allowing the web to recover its original, non-brailled shape.
In order that a visually handicapped person may have an access to the information displayed on a CRT screen, it has been necessary to transcribe the information in braille or pin display characters that can be read via the fingertips. Braille is a system of writing texts as combinations of tangible symbols so devised that the visually handicapped person can read them by touch. The symbols are represented each by a plurality of raised dots in a cell formed on a braille paper made chiefly of pulp fiber.
A pin display is a device for projecting from a plate surface a plurality of pins in suitable combinations in the same arrangement as in braille. Transcription of the information appearing on a CRT screen into braille or pin display characters is a two-step practice, first forming braille codes from the text information using a character/braille conversion software and then driving a braille printer or pin display for printing on braille paper or for pin displaying.
Conventional methods of transcribing the information from a CRT screen into braille or pin displaying have the following drawbacks.
When printing with a braille printer, the braille paper must be replaced by a new, blank sheet each time the display on the CRT screen is shifted from scene to scene. Once printed, the ordinary braille paper cannot be reused, and this adds greatly to the cost of braille displaying of the information from a CRT that handles an enormous volume of data. Pin display, on the other hand, is a device only suited for displaying an amount of information enough for about one line at a time. It takes an unduly long period of time to display a CRT screenful of information. Rebuilding the device to display the whole-screen information would make the construction so complex that the manufacture and maintenance would involve too much difficulties for the realization of the scheme.